Bluish-violet azo dye.



UNITED STATES Patented \Tune 23, 1903.

ATENT "OF ICE.

ADQLF ISRAEL AND OSCAR DRESSEL, OF ELBERFELD, GERMANY, ASSIGNORS TO FARBENFABRIKEN OF ELBERFELD' 00., OF NEW YORK, N.'-Y.,-A COR PORATION OF NEW-YORK.

BLU'ISYH-VIOLET A DYE.

SPECIFICATION forming part r Letters Patent No. 731,460, dated June 23, met;

Applicatioi filed March 31, 1903. Serial No. 150,468. (No specimens.) e

To all whom it may concern.-

' Be it known that we, ADOLF ISRAEL and OSCAR DRESSEL, doctors of philosophyphemists, residing at Elberfeld, Germany, (assignors to the FARBENFABRIKEN or ELBERFELD 00., of New York,) have invented a new and useful Improvement in Bluish-Violet Azo Dyes; and we hereby declare the following to be an exact andclear description of our in- 1.0 v'ention. p

Our. invention relatesto the production of -a new monoazo dyest'ulf by first combining the diazo derivatives obtained from orthochloro-para-amidoacidylanilin, such as the x 5 diazo derivative of acetylchloro-para-phenylenediamin having the formula:

. obtainable'by reduction of ortho-chloro-parae nitroacetauilid (see Aomalen.v d'e'r Chemi'e, Vol. 182, p; 108) withl :S-dioxynaphthalene- 3-6 disulf0nic acid and then splitting ed the 'acidyl by saponification'. According to our researches the samedyestufi can alsobe prepared by first combining the diazotized, meta-chloro-para-nitranilin (see Annalen der- Ohemie,Vol. 182, p. 106) with 1-:8-dioxynaph-V: thalenee3 fi-disulfonic acid and then reducing the resulting monoazo dyestufi in an alkaline solution.

In carrying out our invention we can proceed as follows, the parts being by weight:

40 18.5 parts of acetylchloro-para-phenylenediamin having the above-given formula are diazoti'zed, and the resulting diazo compound is added to a cold solution of thirty-two parts of 1:8-dioxynaphthalen'e-3-fi disulfonic acid mixed with an excess of sodium carbonate.

After thereaction is completed one hundred parts of a sixty-per-cent. caustic-soda lye is .in the shape of the sodium salt, a grayishblackpowdersoluble in water with a reddishvioletcolor, which turns red by the addition added to the reaction mass, and it is heated to the boil in order to split OK the acetyl group. The excess of caustic-soda lye is neutralized by means of hydrochloric acid, and the new coloring-matter is precipitated by the addition of common salt, filtered OE, and driedJIThe dyestufi thus obtained is,

of dilute solutions of ammonia, caustic-soda lye, or sulfuric acid. It issolublefin conceintrated sulfuric acid of 66 Baum with a' reddish-violetcoler, which is changed into yellowish red by the addition of a small quantity of ice, yellow flakes being precipitated by the addition of a larger quantity. of ice. Thenewcoloring-matter dyes wool from acid baths bluish-violet shades fast to light.

Having nowdescribed ourinvention, what we claimis I Theherein-described newgazo dyestuff derived from chloro-para-phenyle nediamin and 1 :S-dioxynaphthalene 3 :6 disulfonic acid,contaiuing the chlorin atom in the molecule in 'meta'position to the azo group, which dye.-

stufi, in the shape of the sodium'salt,.is agrayish-black powder, soluble in water with a reddish-violet color turning red by addition 'of dilute solutions'of ammonia, caustic-soda lye or sulfu ric acid; being soluble in concen trated sulfuric acid of 66 Bauin with a red-' dish-violet color which is changed into yellowish red by addition of a small quantity of ice, yellow flakes being precipitated by the addition of a larger quantity of ice and dye: ing wool from acid baths bluish-violet shades fast to light, substantially as hereinbefore described.

In testimony whereof We have signed our names in the presence of two subscribing wit- Witnesses:

OTTO KONIG, A BERT HEMSING.

Correction in letters Patent No."731,460.-

It'is hereby certified that in Letters Patent N0.'731,460, granted June 23; 1903, upon the application of Adolph Israel and Oscar Dres sel, of Eberfeld, Germany, for an improvement in Bluish-Violet Azo Dyes, an error appears in the printed specification requiring correction, as follotvsi On page 1, I'm-es 17 to 24. the formula shoul d. M.Pt. 133

mfPmsa and that the said Letters Patent Should be read with this correction therein that the 7 same may eohform to the record of the case in the Patent Qfiice.

Signed and sealed this 14th day'of uly, A. D., 1903. I

we] I E. B. MOORE,

' Acting Cmnmssionsr 0] Patents. 

